Lipstick cameras are kind of a double edged sword. The thing about a hidden camera is that you never know what you are going to see when you record people without them knowing. Maybe you will see something hilarious, maybe you will see something horrific.
I have a buddy that suspected his wife may have been cheating on him. He put a lipstick camera in his bedroom every day before he went to work. Sure enough, she was cheating on him and he had to see it all on video. It is one thing to find out it is true, its something much worse to have to watch it in all its tragic detail. Don't mess around with lipstick cameras unless you are prepared to see what they show you.